Concussion Charge

Deals 20-21 elemental damage and pushes up to 5 nearby enemies back away from the Trooper. Targets have their movement speed reduced for 4.0 seconds after being knocked back.

Concussion Charge is an ability available to the Commando player class. Some NPCs may also have this ability, such as the Staff Master. Its not clear if the NPC ability matches the player character ability. For the Staff Master, the combat logs show it triggering a change in threat.